How Fast Can We See? An Eye-Tracking Study on Perceiving High-Frequency Stimuli

Abstract

The exploration of human cognition has fascinated philosophers and scientists for centuries. With the advent of high-frequency computer monitors, it's now possible to present quickly vanishing visual stimuli and investigate whether there is a frequency limit to conscious human perception. Building on studies suggesting that unconscious information processing occurs faster than conscious processing, we examine the potential for unconscious visual information. For that, we designed an eye-tracker experiment comprising several tasks. For that, we design an eye-tracker experiment with several tasks. In the first task, we determine the limits of conscious perception based on a stimulus frequency. In the second, we check the impact of a fast-vanishing (subliminal) stimulus on the reaction times of a saccade task. Finally, in the third, we measure different participants' flicker frequency. From the first task, we found that individuals generally do not consciously register stimuli around $240$ Hz, with the probability of stimulus detection being the least at this frequency. The second task revealed that even unperceived stimuli affect behavior, specifically the reaction times to a visual stimulus. The third task showed that different individuals have varying flicker frequencies. These findings support the hypothesis that unconscious visual information is processed at higher frequencies and that the limits of human perception are highly subject-specific. Our results highlight the significance of high-frequency monitors and prompt new questions regarding inherent individual differences in visual perception. A paper~\parencite{Mathema2024} presenting the findings of this thesis has been accepted for presentation at "The Fifth Workshop on Intelligent Cross-Data Analysis and Retrieval (ICDAR ’24)".